In the manufacturing industry, injection molding is a common process for producing parts. Conventional injection molding often requires the use of a constant-temperature mold, an injection molding machine, and raw molding material or resin (e.g., molten plastic). The mold includes a first mold plate or member and a second mold plate or member that together, define the shape of a part or multiple parts being molded. The injection molding machine is responsible for heating the raw plastic material until liquefied and then injecting the molten plastic into the mold.
The conventional injection molding process generally includes a clamping stage, an injection stage, a cooling stage, and a removal stage. In the clamping stage, the core side and cavity side are clamped shut while the raw plastic is being melted within the injection mold machine. Then, in the injection stage, the molten plastic is injected and packed into the cavity of the mold. In the cooling stage, the mold remains clamped while the molten plastic cools and solidifies into the final or finished part. Finally, in the removal stage, the mold is unclamped and the newly formed part is removed via, for example, one or more ejector pins. After the part is ejected, the cycle is typically repeated.
In some situations, composite parts are formed by molding features into direct contact with previously formed parts. For instance, “insert molding” (e.g., metal insert molding, nanomolding, in-mold metal plastic bonding, etc.) and “overmolding” generally involve placing at least one insert (i.e., the previously formed part) into the mold cavity, clamping the first and second mold members about the insert, injecting a molding material (e.g., high temperature plastics such as polyphenylene sulfide (PPS), polyphthalamide (PPA), and/or the like) into the mold cavity, allowing the mold to cool, and then ejecting the finished part which includes the insert in contact with (e.g., encapsulated by, adjacent to, integrated with, etc.) the solidified plastic material. Currently, overmolding and metal insert molding processes run at constant mold temperatures. When molding plastics such as PPS and PPA, for instance, the constant mold temperature has to be very high in order to yield an acceptable finished product.